Practice Empirical Formula in Chemistry
Use these practice problems to test your method after reviewing the concept explanation and worked examples.
Quick Recap
The simplest whole-number ratio of atoms of each element present in a compound, found by reducing the actual atom counts.
The reduced fraction of atoms—smallest numbers that show the ratio.
Example 1
mediumA compound contains 40.0\% C, 6.7\% H, and 53.3\% O by mass. Determine the empirical formula.
Example 2
hardA compound has empirical formula \text{CH}_2\text{O} and a molar mass of 180\,\text{g/mol}. Find the molecular formula.
Example 3
mediumA compound is 72.0\% Mg and 28.0\% N. Find the empirical formula.
Example 4
mediumA compound is 40.0\% carbon, 6.7\% hydrogen, and 53.3\% oxygen by mass. What is its empirical formula?